I would think it would say "SW" for "Short Wave". Look for a label inside with model number. I would guess the early Philcos are worth $100 or so... more if it has 8 tubes or more...
I have some Philco service bulletins on my web page, but they're '37 and later. This one sounds like '30 or so. Ron Ramirez (MR. Philco) has schematics on his web page -
http://www.mrphilco.com
There's 4 pages of Philco photos here: maybe you can find it:
http://radioatticarchives.com/archive_p1.htm